One female prison guard alleges a male co-worker pushed her over a desk, stuck his hand down her pants and locked a set of handcuffs through her underwear. She says she was put in choke holds and slammed into hard surfaces by her hair.

Another woman alleges she was constantly harassed for being gay and once suffered chemical burns on her buttocks and upper legs after she used a washroom where pepper spray was left on a toilet seat.

The claims are detailed in a lawsuit recently filed by four female guards at Edmonton Institution against the Correctional Service of Canada and the Union of Canadian Correctional Officers.

None of the allegations have been proven in court and statements of defence have yet to be filed.

The suit alleges that sexual assaults, abuse, bullying and harassment were rampant for decades at the maximum-security prison on the northeast edge of the city.

The lawsuit comes after an investigation at the prison last year that concluded the work atmosphere was toxic and made dozens of recommendations for change.

In January, the Correctional Service announced that it had fired six employees, hired a new warden, improved training and created a confidential tip line for employees to report misconduct.

Both the department and the union said in statements Monday that while they can't comment on the suit, they do not tolerate harassment. As well, Edmonton police continue to investigate possible criminal charges in the case.

The Correctional Service "has given itself a veil of secrecy, which managers, senior employees and the union have used to harass and intimidate employees, thus far with immunity," the lawsuit alleges.

"Under this veil, the plaintiffs have been harmed with disastrous, life-altering consequences and the defendants utterly failed them."

The suit says three of the women have been diagnosed with post-traumatic stress disorder and are not working at the prison. The fourth continues to work part-time, but finds putting on her uniform each day difficult.

The suit does not detail how the waterboarding happened. In general, waterboarding is the name given to a practice where someone is tied down and water is poured over their face to simulate drowning.

Jeffrey O'Brien, the lawyer representing the women, declined to comment and said the women would not be speaking either. The women are not named in the claim "due to the confidential and secretive nature of law enforcement work," the suit says.

The alleged perpetrators are not referred to by name in the suit.

The suit says one of the men harassed one of the female guards each day for nearly 10 years. It alleges he often pulled his penis out of his pants and chased her around the office. And when she was having a drink, he told her that he had stirred it with his penis.

He also once allegedly left open a bathroom door near her desk as he defecated. Another officer then forced her into the bathroom and shoved her face under the man's buttocks, the suit alleges.

"Both men laughed while she screamed and struggled," says the suit.

The suit further alleges that another guard stalked the same woman, touched her inappropriately at work and left sex toys in her car.

She "lived in constant fear of reprisal so she never spoke out," the suit says. "Taking this matter to the union was not an option, because her abusers had positions within the union."